Applicable Years:
1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985
Engine Code Primary:
M110
Engine Code Variants:
M110.984 (2.8L)
Positioning:
The Mercedes-Benz 280E (W123) was positioned as a robust, luxurious, and technically advanced executive sedan in its era.
Competitors:
Competed with other premium sedans of the period such as BMW 5 Series, Audi 100, and Jaguar XJ.
Distinctiveness:
Renowned for its build quality, durability, sophisticated engineering, and comfortable ride.
Significance:
Represents a significant era for Mercedes-Benz, known for its timeless design and engineering excellence.
Target Audience:
Owners, mechanics, and enthusiasts seeking to maintain and repair their classic Mercedes-Benz 280E.
Engine:
Complete overhaul, tuning, fuel injection (Bosch K-Jetronic), ignition system, cooling, lubrication.
Transmission:
Manual and automatic transmission repair, clutch, driveshaft, differential.
Brakes:
Hydraulic system, brake calipers, master cylinder, parking brake, ABS (if equipped).
Suspension Steering:
Front and rear suspension, power steering, steering gear, wheel alignment.
Electrical:
Wiring diagrams, starter, alternator, battery, lighting, instrumentation, power windows, central locking.
Body Chassis:
Body repair, doors, hood, trunk, glass, bumpers, chassis lubrication.
Maintenance:
Scheduled maintenance, oil changes, filter replacements, tune-ups, fluid checks.
Diagnostics:
Troubleshooting guides, fault diagnosis for engine, transmission, electrical systems.
Repair:
Detailed step-by-step repair instructions for all major components.
Rebuilds:
Engine and transmission rebuild procedures, including component specifications and tolerances.
Adjustments:
Carburetor adjustments, fuel injection system adjustments, ignition timing adjustments.
Depth:
Comprehensive, from basic maintenance to complete engine and transmission overhauls, including advanced diagnostics.
Engine Type:
Inline-6 Cylinder, SOHC
Displacement:
2746 cc (2.8 Liters)
Bore X Stroke:
86.0 mm x 79.0 mm
Compression Ratio:
8.0:1 (typical)
Horsepower:
185 PS (approx. 182 hp) at 5800 rpm (DIN)
Torque:
23.5 kg⋅m (approx. 230 Nm or 170 lb-ft) at 4000 rpm (DIN)
Fuel Delivery:
Bosch K-Jetronic Mechanical Fuel Injection
Fuel Type:
Unleaded Gasoline (Octane rating typically 91-98 RON)
Oil Capacity:
7.0 Liters (7.4 US Quarts) with filter
Coolant Capacity:
Approx. 10.0 Liters (10.6 US Quarts)
Transmission Type:
4-speed Manual Transmission (M-B Type 717.400)
Transmission Type:
4-speed Automatic Transmission (optional) (M-B Type 722.1)
Auto Transmission Features:
Hydraulic torque converter, often with a selector for Economy/Standard modes.
Automatic Transmission Fluid:
MB 236.2 (e.g., Dexron II compatible)
Manual Transmission Fluid:
MB 235.1 (GL-4 SAE 80/90 Gear Oil)
Crash Test Data:
No standardized crash test ratings (e.g., NHTSA, Euro NCAP) readily available for this era, but known for robust construction.
Brakes:
Front ventilated disc brakes, rear solid disc brakes. Optional ABS on later models.
Steering:
Recirculating ball power steering (standard or optional depending on year/market).
Body Structure:
Reinforced safety cell, impact-absorbing steering column, side-impact protection beams (in later W123s).
Restraints:
Seat belts (front and rear). Airbags were not standard on most W123 models.
Audio System:
Typically an AM/FM radio with cassette player. High-end options might include premium sound systems.
Climate Control:
Manual ventilation and heating. Optional automatic climate control (Thermotronic) on higher trims or later models, often vacuum-actuated.
ABS:
Anti-lock Braking System (ABS) became available as an option on later models, typically from the mid-1980s.
Connectivity Features:
Limited by era. Key features would include power windows, power door locks (often vacuum-operated), cruise control (optional).
Oil Change Interval:
Every 10,000-15,000 km (6,000-9,000 miles) or 12 months, whichever comes first.
Air Filter Replacement:
Every 30,000-40,000 km (18,000-25,000 miles).
Fuel Filter Replacement:
Every 30,000-40,000 km (18,000-25,000 miles).
Spark Plug Replacement:
Every 40,000-60,000 km (25,000-37,000 miles).
Transmission Fluid Change:
Automatic: Every 40,000-60,000 km (25,000-37,000 miles). Manual: Inspect at 60,000 km, replace if needed.
Engine Oil Grade:
API SG/SH or higher; SAE 10W-40 or 15W-40 recommended for general use. Consult manual for specific climate recommendations (e.g., 5W-40 for cold).
Coolant Type:
Ethylene glycol-based coolant, mixed 50/50 with distilled water.
Brake Fluid Type:
DOT 3 or DOT 4.
Common Problems:
Rust (especially wheel arches, jacking points, door bottoms), vacuum line deterioration (affecting central locking, climate control), distributor O-ring leaks, K-Jetronic fuel distributor issues, valve stem seals (oil consumption).
Preventative Measures:
Regular rust proofing, diligent inspection and replacement of rubber vacuum hoses, consistent fluid changes, and using quality replacement parts.
Heritage:
Mercedes-Benz has a long-standing reputation for engineering excellence, safety, and luxury vehicles.
W123 Introduction:
The W123 series was introduced in 1975, succeeding the W114/W115 series and serving as Mercedes-Benz's mid-size executive car until 1986.
280E Variant:
The 280E, with its M110 engine, represented the upper tier of the gasoline-powered W123 lineup, offering strong performance.
Production Period:
1975–1985 (for W123 sedan and coupe variants, including 280E)
Manufacturing Locations:
Mainly Germany, with some assembly in other global locations.
Durability:
The W123 is legendary for its robust engineering and longevity, often referred to as one of the most durable Mercedes-Benz models ever built.
Industry Accolades:
The W123 series received numerous accolades for its build quality, safety, and reliability during its production run and continues to be highly regarded by automotive critics and enthusiasts.
Reliability Ratings:
Consistently ranked among the most reliable cars of its era by automotive publications and owner surveys.
Certification Programs:
N/A in the modern sense of crash-test certifications, but adhered to stringent Mercedes-Benz internal engineering and safety standards of the time.
